1. Field of the Invention
The present invention relates to an exposure indication system for interchangeable lens cameras, and more particularly pertains to such an indicating system which indicates a diaphragm aperture suitable for scene brightness and set exposure factors such as shutter speed and film sensitivity.
2. Description of the Prior Art
Indicating systems are known which indicate not only a diaphragm aperture suitable for scene brightness and set exposure factors, but also whether the suitable diaphragm aperture is within or outside a diaphragm aperture range available for the interchangeable lens mounted on the camera in which the indicating system is employed. (see, for example, U.S. Pat. No. 4,087,829). However, the known systems provide an indication of the diaphragm aperture that is outside the diaphragm range available for the interchangeable lens, along with the indication that the diaphragm aperture indicated is outside the range, when the diaphragm aperture to be indicated is outside the range but within the indicatable range. For, example, for an interchangeable lens having a diaphragm aperture range from F 2.8 to F 16 associated with a diaphragm indicating system capable of indicating from F 1.4 to F 32, indication of F 2 as well as out-of-range indication will be made when the suitable aperture is F 22. These double indications are likely to cause confusion to the user. In case the diaphragm indicating system is associated with an automatic diaphragm control divice to indicate an automatically controlled diaphragm, the camera operator might understand from the indication that the diaphragm will be determined to the indicated aperture which, in fact, is not available for the interchangeable lens.